Process for treating froth flotation concentrates



ma orar/aar @065,103

Jan. 5, 1954 A. W. ZUKOSKY PROCESS FOR TREATING FROTH FLOTATION CONCENTRATES Filed April 11. 1949 s/vro/wre ryPe' CL@ Y Mme-Am: Pano v aN/w//v//VG 01.55497- M Zu/ros/rr @wa/Mom ATTORNEYS Patented Jan. 5, 1954 PROCESS FOR TREATINGFROTH FLOTA- TION CONCENTRATES Albert W. Zukosky, Burnsville, N. C. .Y

Application April 11, 1949, Serial N o. 86,811

Claims. 1

The use of sink-and-iloat concentration operations for effecting concentration of ores and minerals is well-known. Among such operations there are commonly employed froth flotation procedures, wherein lighter constituents of a mineral body or the like being concentrated are suspended in a foam or froth produced by the use of foam-producing reagents, such foam having sufficient viscosity to float off lighter particles of the mineral body being concentrated while allowing heavier particles to sink through the foam and reagents for settling into the bottom of the tank or cell in which the operation is carried out.

In accordance with the usually resorted to procedures employing froth flotation of non-metallic minerals, it often happens that the valuable mineral is obtained from the flotation cells associated with the froth, and it is found that after dewatering and drying, the resulting concentrates still contain flotation reagents, whichmay be an impedance in the further processing of the concentrates, or at least in a loss of valuable reagents. For example, the presence of these reagents on the concentrates prevents them from being wholly wettable with water, and also tend to reform the concentrates into a froth or foam, particularly in circumstances Where the concentrates -may be re-pulped in Water for further processing. In many industries using these nonmetallic minerals which have been concentrated by flotation, this feature is very troublesome and in some circumstances, actually prevents the use of the concentrates. This is particularly true in the ceramic industry where, in most cases, the mineral necessarily has to be re-slurried with water and agitated. In these cases, the froth or foam produced by the residual flotation reagents left on the mineral particles provides a most difficult problem in obtaining a good casting or workable slip or slurry of the mineral or of a composition where a fiotation concentrated mineral forms a slip or slurry.

The present invention relates to a process for removing such residual flotation reagents from flotation froths or pulps containing flotation reagents, and the invention has for one of its objects rendering the mineral concentrates from froth flotation operations `completely free from residual contained notation reagents so that such concentrates may be fully water-wettable and,

unable to reform into froth by the addition of air and water.

A further object of this invention is to de-oil notation froths containing non-metallic minerals y2 which have been floated with a class of flotation reagents known asvcationic or amine type reagents commonly used to float non-metallic miny erals.

Further robjects of the invention will become apparent as the description proceeds, and the features of novelty will be pointed out in particularity in the appended claims.

In accordance with the present invention, 'it has been discovered that such concentrates can be freed effectively from entrained or occluded froth-producing reagents by the addition of adsorbent clays such as bentonite or the like during the re-pulping and agitation of the concentrates, or that the flotation concentrates can be treated at the flotation plant by agitating the froth with bentonite. In this way, the froth-forming tendencies of the mineral concentrates are completely destroyed, and the concentrates then may be wetted completely with water and aerated in a f water slurry without any tendency tofform a froth.

A further feature of the present invention resides in the discovery that the incorporation of a small amount of lime, alkalies, or alkalinereacting compounds in combinationl with the adsorbent clays, further improvesv the waterwetting tendencies of the mineral concentrates.

Such addition of alkaline-reacting compounds' also neutralizes any acid which usuallyis employed in flotation concentration of non-metallic minerals using cationic-type reagents.

'Ijhe procedure of the present invention will be understood more readily by reference to the accompanying drawing, which illustrates in diagrammatic manner, a flow sheet illustrating the operational steps of the process of the invention.

In accordance with the drawing, a slurry of bentonite is prepared in ay suitable tank or receptacle l, and a' water solution of a suitable alkali or alkaline earth compound is prepared in tank 2. These solutions are flowed together into an agitator 3 which is fed a pulp of the mineral concentrates containing flotation reagents. The materials are mixed thoroughly, together by means of a propeller-type agitator Il, and preferably overflow into a second and similar agitation tank 5 provided with a propeller-typeagitator 6. The resulting mixed slurry passesto a classifier 'l, wherein the flotation reagents and the concentrates become separated and stratified, the resulting reagentefree concentrates settling to the bottom of the classifier as indicated and with` drawn therefrom, whereas water, the frothing reagents and adsorbent clay are withdrawn from trates being employed, and consequently the fol- .15

lowing examples are to be regarded `as 'being typically representative of thezprosszfasaetually carried out.

Example I A feidsar from which had been coated with hydroiiuoric acid and ArmacT (an aminecationic type reagent) which possessed strong frothforming'properties was treated withv 0.75 'pound per ton (dry basis) bentonite, and with 0.25 pound V*per lton (dry-basis) lime and 35 per cent solidsasawater'slurry in 'an agitator fortwo minutes. It wasfoun'dthat this treatment 'removed completely all traces of the reagents,'and the feldspar was wetted easily with water and showed no'tendency tore-form a froth upon addition of air 'while beinga'gitated.

.Example II 'A 'mica concentratein 1:froth form was treated with '-1 'poundfperf ton (dry basis) bentonite-and 0.5 pound' per ton of lime' (dry basis) vand-'agitated two 1ninutesat25'per cent solids as a water slurry. It was -found that this *treatment removed-al1 reagentsand acids and l'renderedthe micacompletely'*water-wettable, -with yno 4frothforming-tendencies-when aerate'd as in-a water slurry.

Example III A sericite concentrate in .froth .foam was treated with '1.0 ,pound per .ton .(drybasis) 4-bentonite and l pound per tonf lime (dry'basis) and agitated for three minutes at. 20 per cent .solids as a water slurry. It was found thatthis treatment removedall reagentsandmadethe ser-icite completely water-wettable.

Example .1V

A feldspar 'concentrate in froth`foamwas-agi tated'for 'twominutesias'a'water slurry of .30, per cent solids'with f3 pounds ,per ton of sub.- bentonite type clay and 0.`5"pound perlton sodium hydroxideithe weights being 'on a drybasis). It was Jfound =that"'this treatment removed `all traces'of the reagents and made Athe feldspar completely water-wettable.

Example vV fA-eeramic 'pulp'compose'd of feldspar 30fper cent.clay 30 per cent, 'flint'30 per cent, and ball clay per centy-was prepared, 'using notation concentrated feldspar with theresidualflotation reagents stillcontained on theparticles'of feldspar. L'Ihisrpuip on vagitation andfaeration ha'd froth4forming properties 'to Aan extent to Hmalte it unworkable. Thispulpthenfwastreatedwith 3 pounds ,parten '(dry'basis) lbentoni-teand 0:25 Pound .per ton ylime Atand :agitatedffor :two 'minutes withal propeller-type lagitator. 'Upon -removing the pulp-from'the agitator'itfwasitreated again `with air and was .found Ato be :freefrom froth-forming tendencies, the pulp being found to be readily workable from a ceramic viewpoint.

In the foregoing examples, lime or caustic soda was used in connection with bentonite. As has been pointed out above, such alkaline reacting materials are found to be helpful as neutralizing agents for acidic constituents in froth-producing reagents, although in instances when such acidic constituents a're eabsent, 'ithe presaice of such aikalinematerials' is not necessary. Where such materials are employed, lime is found to be prefuerable to caustic soda as the neutralizing agent, it-'beingimoreeasilyhandled and being less corvrosi'vetwthe equipment employed. It is found in practice that bentonite is the preferred de- 'oilin'g'materialfor the concentrates, its absorbentzaotionffonthe-froth-forming materials being substantially greater than that of the particles ofi'thefmin'eral concentrates being treated.

While from the foregoing it will be apparent that preferreduembodiment -of i the improved process Yemploys@bentonite .'astheV froth-releasing material, :the Vquantities Ltheneof 'lthat Vare preferred will depend upon the 'particular-type of concentrates being: treated as .'well as 'the `amount of frothproducing reagents vassociated therewith.

VAccordingly,'it will'be understood that'it is intendedl and `.lesiredto embrace 'within the scope of the invention such modifications and-changes asv may= be necessary to .adapt itlto varying fconditions and uses. as donned by thealppen'ded claims.

Having thus described my .'inventton, what 'I desirerprotected byiIlettersiPatentlishasfset forth in the following claims:

l.1. .Aprocess-for-removing amlnenotation reagents from -coutainingzliotationfroths of micaceousa-nd: fel'clspathie :cmncentratesv :containing residual 1 flotation zreagents,` lwhich ..co'rnprises adding :bentonite (to the A.sain pulp fof` the micaceous and .feidspathic'concentrates for adsorbingvthe amine 'ilotationereagentsfrom vthelsaid concentrates, classifying 'the fresulting treated concentrates and bentonite, .and separating-'the resulting =reagent-freed Aconcentrates 'and liquid bearing. mineral material "andl'otation reagents adsorbed zthereon.

2. .A process. ifor removing famine containing flotation .reagents Ifrom :amine "containing flotation'froths4 of micaceous and Vfeldspathic lconcentrates .containing .residual notation reagents, which comprises adding to aan aminecontaining pulp A.of micaceous :and .feldspathiefconcentrates an .adsorbent bentonite clay furfadsorbi'ng 'the fiotation reagents from 'the said '.corrcentrates, classifying .the resulting treated vconter:trates' 'and bentonite. clay, and :separating the resultingE reafgent-.freed concentrates Aand liquid bearing the bentonite `clay yand flotation .reagents ladsorbe'd thereon.

Il.. Iniroth notation .concentration operations,

the improvements which-consist in treating an amine-Containing .pulp-of micaeeous and ffel'dspathic concentrates containing-residual aminecontaining .flotation reagents :with :bentonite ffor freeing the concentrates from "the residual lrea- 4O5- ffgents, and. agitating` thehentonite: and` .pulp until famin'e-containing pulp of .silicate .concentrates selected `Nfrom the group consisting of -mica .and feldspar containing residual aminefcontaining flotation reagents with .bentonite` and an. alkaline material 'forfreeingi the said silicate concentrates dromtheresidual-aminecontaining reagents. and

agitating the pulp with the bentonite and alkaline material until acidic constituents in the reagents are neutralized and the reagents are separated from the concentrates.

5. In froth flotation concentration operations, the improvements which consist in treating a pulp of non-metallic silicate concentrates selected from the group consisting of mica and feldspar containing residual amine-containing flotation reagents with about 0.75 pound to about 3 pounds of adsorbent bentonite clay per ton of concentrates on a dry basis, agitating the pulp and bentonite until the said concentrates are free from the amine-containing flotation reagents, and separating the thus-treated concentrates from associated materials.

6. A process for removing residual amine-containing flotation reagents from froth dotation silicate concentrates selected from the group consisting of mica and feldspar, which comprises, agitating the concentrates as a water slurry with bentonite-type clay and an alkaline compound until the residual amine-containing reagents are separated from the concentrates, and recovering the thus-treated concentrates from associated materials.

7. A process for removing residual amine-containing reagents from froth flotation silicate concentrates, selected from the group consisting of mica and feldspar, which comprises agitating the said silicate concentrates as a water slurry with bentonite and lime until the residual amine-containing reagents are separated from the concentrates, and recovering the thus-treated concentrates from associated materials.

8. The process of de-oiling flotation micaceous and feldspathic pulps, which comprises conditioning the pulps as a Water slurry by agitating the slurry with bentonite.

9. The process of de-oiling froth flotation silicate pulps selected from the gro-up consisting of mica and feldspar obtained from amine-containing flotation reagents and mineral acid reagents, and which pulps contain residual amine-containing reagents, which comprises agitating the said pulps with bentonite and a water-soluble alkaline material for neutralizing the mineral acid reagents until the said pulp is freed from residual flotation reagents and the acid reagents therein are neutralized, and separating the thus-treated minerals from resulting associated materials.

10. The process of treating a ceramic slip which has froth forming properties resulting from the presence in the slip of amine-containing froth flotation mineral silicate concentrate selected from the group consisting of mica and feldspar and containing residual amine-containing froth forming reagents, which comprises agitating the slip with bentonite until froth-forming tendencies are removed from the slip, and recovering the thus-treated slip from associated materials.

11. In the treatment of froth flotation concentrates selected from the group consisting of mica and feldspar and containing residual amine-type froth-producing reagents, the improvements which consist in producing an aqueous slurry of the said concentrates, agitating the slurry with bentonite until the reagents are separated from the concentrates, and recovering the said concentrates free from associated materials.

6 12. The process for removing amine-containing flotation reagents from froth notation silicate concentrates selected from the group consisting of mica and feldspar containing residual centrates, and recovering the resulting reagent free concentrates.

13. The process for removing flotation reagents from amine-containing froth flotation silicate concentrates selected from the group consisting of mica and feldspar containing residual froth forming reagents, which comprises adding bentonite to an aqueous pulp of the said concentrates and lime in an amount sufficient to neutralize acidic constituents in the said residual reagents, agitating the bentonite and the pulp together until the residual reagents are separated from the concentrates, and recovering the resulting free concentrates.

14. The process for removing amine-containflotation reagents from amine-containing froth notation silicate concentrates selected from the group consisting of mica and feldspar containing residual froth forming reagents, which comprises adding bentonite to an aqueous pulp of the said concentrates and caustic soda in an amount sufficient to neutralize acidic constituents in the said residual reagents, agitating the adsorbent material and the pulp together until the residual reagents are separated from the concentrates, and recovering the resulting reagent-free concentrates.

15. The process for removing amine-containing flotation reagents from amine-containing froth flotation silicate concentrates selected from the group consisting of mica and feldspar containing residual amine-containing froth forming reagents, which comprises adding to an Y aqueous pulp of the said concentrates bentonite and caustic soda in an amount suliicient to neutralize acidic constituents in the said residual reagents, agitating the adsorbent material and the pulp together until the residual reagents are separated from the concentrates, and recovering the resulting reagent-free concentrates.

ALBERT W. ZUKOSKY.

References Cited in the file of this patent UNITED STATES PATENTS McGraw-Hill Book Co. 

3. IN FROTH FLOTATION CONCENTRATION OPERATIONS, THE IMPROVEMENTS WHICH CONSIST IN TREATING AN AMINE-CONTAINING PULP OF MICACEOUS AND FELDSPATHIC CONCENTRATES CONTAINING RESIDUAL AMINECONTAINING FLOTATION REAGENTS WITH BENTONITE FOR FREEING THE CONCENTRATES FROM THE RESIDUAL REAGENTS, AND AGITATING THE BENTONITE AND PULP UNTIL THE AMINE-CONTAINING FLOTATION REAGENTS ARE SEPARATED FROM THE CONCENTRATES. 